Process of manufacturing triaryl phosphates



for example sodium hydroxide preferably in Patented Dec. 15 1931 UNI EDQSTATES PATE wILLIaJa 2. TE], nozas'r, or mmo, wnsrvmomm, ASSIGNOR momma ELKQ camp CAL com any, ormrao, WEST vmemm, A CORPORATION or WEST IRGINIA j "Processor massacres-me TRiARYL rnosrna'ms This inventiorlrelates to the manufacture of triaryl phosphates and hasfor its object to provide an improved process whereby these arylestersmay be producedin a state 5 of highpurity and in an economical and eflicient manner. More specifically the present invention relates to the preparation of triaryl phos hates by an improved process whereby phosphorus oxychloride is added to an aqueous solution of a metallic salt of a phenol, formed by reactinga phenol w-ith a water soluble metallic hydroxide to which a relatively-small proportion of an inert organic solvent was added. V V V In the preparation of triaryl phosphate as hereinafter described,tthe organic solvent is. added "for the purpose of preventing the monochloride of the diaryl' phosphate from separating out thereby preventing the reaction with a third molecule of an alkali salt of a phenol to form triarylfphosphateQ In the case of the reaction between phosphorus orzychloride andan alkali phenate, if water only is usedas a solvent,,the' monochloride of diphenyl phosphate is produced. In other words, two mols of an alkali phenate react with one mol of phosphorus oxychloride to form one mol of the monochlorideof diphenyl phosphate, which being insoluble in water, separates out and the reaction stops; On the addition-of a small amount ofan organic solvent inwhich the monochlorideof diphenyl phosphate is soluble, a reaction ber tween one mol of the monochloridefof diphenyl phosphate andone mol of an alkali consequent phenate 1 takes I place with the formation of-triphenyl phosphate;

One of the preferred class of compounds, for example, triphenyl' phosphate was preparedin the following manner:

Approximately three molecular proportions (28 2 partslof phenol were dissolved in an aqueous solution of agca'ustic alkali," as

the proportion of 'IQDpart-s (3 molecular proportions), dissolved in approximatelytwice its weight of water Approximately 150 parts "of water were added and then substantially 30 parts of an inert organic solvent, for example xylene, were added. To

instead being added to asu'cceeding Applicatibnfiled Julie 19, 1928. Serial m5, 286,718.

V mately one molecular proportion" (153 parts) of phosphorus oxychloride was added with agitation while maintaining a tern erature o substantiallyO to 3 After t e addition ofsthe phosphorus oxychloride was completed, agitation was continued for substantiallyithree hours at a temperature of ap proximately 0 to 3 C. Atthe end of the reaction-the solid present, containing both triphenyl phosphate and sodium chloride, was separated fromthe liquid present by any well known means, for example by filtering. Thefiltratewas extracted with an organic solvent, forexampl'e xylene, and the solid "residue containin both triphenyl phosphate and sodium chloride crystals waslikewise extracted with" an organic solvent, for example xylene, toseparate the triphenyl phosphate from the inorganic chloride. If desirable or convenient, the solvent extrac't from the'filtrate may be emplo ed toextract the triphenyl phosphate rom the hereinbefore mentioned residue. "All solvent extracts were-combined and thetriphenyl phosphate 'any'convenient method, such forexample,

as by distillation or by concentrating the filtratefcoolin'g and filtering the precipitated triphenyl phosphate therefrom. 'If desirable, no attempt need be made to separate portion' ofiphosphorus oxychloride 1n the filtrate from the first filtration, said filtrate run of tripheny'l phosphate to be made. i

Triphenyl phosphate prepared as desc r'ibed i has been. isolated from the reaction roduct by other means than that hereiiibe ore described, as by distillation at reduced pres- Y sure. -:Tripl1 enyl phosphate obtained according'to the methoddescribed "is of'an exceptionally high qualityas-after recrystallizw" tion it contains no pheno1odor,'and does'not discolor substantiallyi when e ose'd for twelve hours in a closed quartz tu to ultra violet light "generated bya mercury vapor are operating on a 110 volt cyclecircuit.

Me in the above equations represents an alkali metal. V

Another of the preferred type of compounds, tricresyl phosphate, has been repared in a manner similar to that descri ed. Thus, approximately three molecular proportions (32 & parts) of ortho cresol were dissolved-inan aqueous solution of a" caustic alkalias for example sodium hydroxide'pref- .erably in the proportion of. 120 parts (3 molecular proportions) dissolved in approximately twice its weight-of water. Approximately l parts of water were added and then substantially 30 parts of an inert oranic solvent, for example xylene, was added. 0 this solution, approximately one molecular proportion (l53-parts) of phosphorus oxychloride was added with agitation at a temperature of substantially 0 to 8 C. Agitation was then continued for substantially three hours at. a temperature of approximately 0 to 3? C. At the end of this period any acid presentin the reaction product was nleutralized' and the material allowed to sett e.

The reaction product comprised two liquid layers, The upper layer, containing tricrejsyl phosphate together with a small amount I of organic solvent, was separated and dried most purposes,

solvent zimpurity may first be eliminated, as for example by'distillation at reduced preswith a dehydrating a ent,,as for example This dried maanhydrous sodium sul ate. terial has been found to be satisfactory for If. desirable, however, the

sure, and the residual liquid then dried as hereinbefore described.

Other metallic hydrates than sodium hydroxide may be used in the preparation of triarylphosphatesaccording to the process herembefore described; Thus, lime may be substituted for sodium hydroxide as shown in the following example:

Approximately three molecular proportions (282 parts) of phenol were dissolved in substantially 1600 parts of water, 92 parts of lime (approximately l0% excess over substantially one and one-half molecular proportions) were added and then substantially 100 parts of an inert organic solvent, for example xylene, added. To this solution hereinbefore described, approximately one molecular proportion (153 parts) of phos phorous oxychloride was added with agitation while maintaining a temperature of substantially O to 3 C. After the additional of the phosphorus oxychloride was completed, agitation was continued for substantially three hours at a temperature of approximately 0 to 3 C. On the completion of the reaction, the triphenyl phosphate thus formed was isolated according to the method hereinbefore described.

What is claimed is:

1. A process for the manufacture of a tri'aryl phosphate comprising the reaction between approximately three molecular proportions of an alkaline-reacting salt of a phenol and approximately one molecular proportion of phosphorus oxychloride in the presence of a substantial quantity of water and a lesser proportion of an organic solvent of any monochloride of a diaryl phosphate 'therebyproduced and inert towards said reacting components.

2. A process for the manufacture of a triaryl phosphate comprising the reaction between approximately three molecular proportions of the sodium salt of a phenol and approximately one molecular proportion of phosphorus oxychloride in the presence of a substantial quantity of water and a lesser proportion of an organic V solvent of any monochloride of a diaryl phosphate thereby produced and inert towards said reacting components.

3. A process for the manufacture of a triaryl phosphate comprising the reaction between approximately three molecular pro portions of the sodium salt of a phenol and approximately one molecular proportion of phosphorus oxychloride in the presence of a substantial quantity of water and a lesser proportion of an organic hydrocarbon solvent at a temperature of approximately 0 to 3 C. V

4. A process for the manufacture of triphenylphosphate comprising the reaction between approximately three molecular proportions of an alkaline-reacting salt of phenol and approximately one molecular proportion of phosphorus oxychloride in the presence of a substantial quantity of water and a lesser proportion of an organic hydrocarbon solvent.

5, A process for the manufacture of triphenyl phosphate comprising the reaction between approximately three molecular pro portions of sodium phenate and aproximate- 1y one molecular proportion of phosphorus oxychloride in the presence of a substantial quantity of water and a lesser proportion of an organic hydrocarbon solvent at a temperature of substantially to 3 C.

6. A process for the manufacture of triphenyl phosphate comprising the reaction between approximately three molecular proportions of sodium phenate and approximately one molecular proportion of phosphorus oxychloride ,in the presence of a substantial quantity of water and a lesser proportion of xylene. r V

7 A process for the manufacture of triphenyl phosphate comprising the reaction between approximately three molecular pro- 2 portions of sodium phenate and approximately one molecular proportion of phosphorus oxychloride in the presence of a substantial quantity of water and a lesser proportion of xylene at a temperature of substantially 0 to 8. A process for the manufacture of atriaryl phosphate comprising the reaction between approximately three molecular proportions of a salt of a phenol, formed by reacting a metallic water soluble hydrate with a phenol, and approximately one molecular proportion of phosphorus oxychloride in the presence of a substantial quantity of water and a lesser quantity of an organic solvent of any monochloride of a diaryl phosphate thereby produced and inert towards said'reacting components.

9. A process for the manufacture of triphenyl phosphate which comprises reacting 40 approximately three molecular proportions of sodium phenate and approximately one molecular proportion of phosphorus oxychloride in the presence of wateriand a lesser quantity of an organic solvent of an incompletely phenylated phosphate.

10.- A process for the manufacture of triphenyl phosphate which comprises reacting approximately three molecular proportions of sodium phenate and approximately one molecular proportion of phosphorus oxychloride in the presence of water and of, an organic solvent, of a phenylated phosphate immiscible with water. i

In testimony whereof I hereunto aflix my signature. 7 a

WILLIAM P. 'rnn HORST. 

